LONDON (Reuters) - Pregnant women who occasionally
overindulge in a night of drinking may not be harming their
fetuses but more evidence is needed to determine whether this
is really the case, British researchers said on Wednesday.

A review of 14 studies also suggested children whose
mothers binge drank throughout pregnancy may suffer learning
problems later in life, prompting a call for further research
to see if any links exist.

"Just because we haven't been able to find much evidence
doesn't mean there is no effect," said Ron Gray, a clinical
epidemiologist at the University of Oxford, who led the study.
"Our view is there needs to be more research."

A number of studies have linked heavy drinking on a regular
basis during pregnancy to stunted growth, birth defects and
brain development problems.

Less clear is the effect of occasional binge drinking,
which amounted to about 5 drinks in one session in the studies
Gray and his team reviewed.

The researchers initially identified more than 3,500
scientific papers between 1970 and 2005 looking at pregnancy
and alcohol, which they winnowed down to 14 focusing on binge
drinking.

LITTLE EVIDENCE

They found little substantive evidence binge drinking once
in a while caused problems such as miscarriage, stillbirth,
abnormal birth weight, or birth defects such as fetal alcohol
syndrome.

"However, this study only counted women as bingers if they
binged throughout pregnancy, not just on a single occasion,"
the researchers wrote.

Animal studies have shown harmful effects from binge
drinking, which means pregnant women should still take care no
matter how much they consume, Gray said.

At the same time until researchers have more evidence,
women who binge drink on occasion should not fret unnecessarily
about potential harm they are causing to their fetuses, he
added.

"When pregnant women report isolated episodes of
binge-drinking in the absence of a consistently high daily
alcohol intake, as is often the case, it is important to avoid
inducing unnecessary anxiety as, at present, the evidence of
risk seems minimal," the researchers wrote.